At December 31, 2017, Spearmint Inc. had 300,000 common shares outstanding (no preferred shares issued). In addition, the corporation had granted 90,000 stock options to certain executives, and which gave them the right to purchase Spearmints shares at the option price of $37 per share. None of these options have yet been exercised. The average market price of Spaniel's common shares during 2017 was $50. What is the number of shares that should be used in calculating diluted earnings per share for 2017?

A) 300,000

B) 323,400

C) 331,622

D) 366,600